The Bangkok Metropolitan Administration (BMA) said the switch is in line with Public Health Ministry guidelines for Dark Red Zone provinces of high infections and controls.
Giving Sinovac as a first dose followed by AstraZeneca as the second dose could be done in three weeks instead of the 12-week gap required for two AstraZeneca jabs, explained the BMA.
The Cabinet on Tuesday approved a budget of 4.25 billion baht to procure another 12 million doses of Sinovac for the mix-and-match programme.
The BMA said 59,238 Covid-19 vaccine jabs were administered in the capital on Wednesday, taking the total number of doses administered in Bangkok to almost 10 million (9,872,041 doses).